Mattress with backrest



FIG. 1 is a front and top perspective view of a mattress with backrest,showing my new design;

FIG. 2 is a rear and bottom perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a front elevational view thereof; and,

FIG. 8 is a rear elevational view thereof.

The broken lines in the figures illustrate portions of the mattress withbackrest that form no part of the claimed design.

CLAIM The ornamental design for a mattress with backrest, as shown anddescribed.